TL;DR: These are not 669 files. It's jut a coincidence they were identified as such.
Explanation: To me that looks like whatever tool your used for extracting just scanned through that executable and hinged on the two possible and unfortunately very short "magic byte" sequences of the 669 format. The files you extracted start with the correct two-byte sequence that would indicate a valid 669 file ("if" or "JN"), but whatever follows after two bytes is just garbage. I'm not aware of any games using 669 files for music playback at all, and the fact that two of those files start with "JN" and the other two with "if" just makes it even more likely that this is a random coincidence (if someone was going to write a soundtrack for a game, they'd probably stick to either Composer 669 with its "if" magic bytes or UNIS 669 with its "JN" magic bytes but not use both programs). If you scan a large executable, it's not unlikely at all that if you look long enough, you will somewhere find the two bytes "if" somewhere in the middle of the file, so that's probably what this tool did.
If you reveal which game you wanted to extract music from, you could probably get a better reply.
